Operation Sea Lion in fiction

There is a large body of fiction set in an alternate history or a secret history, where the Operation Sea Lion, a German plan of invasion of Britain during World War II, is attempted or successfully carried out.

Literature

Against the Day, Through the Night and In the Morning by Michael Cronin
And all the King's Men, a 1990 novel by Gordon Stevens.
Collaborator, a 2003 novel by Murray Davies.
Gold from Crete, C. S. Forester's 1971 volume of short stories includes "If Hitler had invaded England". This follows the progress of a German invasion fleet from its embarkation in France to its destruction in the fields of Kent, and closely follows the sequence of events reported in the Sandhurst wargame three years later.
In the manga Hellsing the remnant of SS known as Millennium dub their attack of London Operation Sea Lion II. Prior to the attack, the leader of Millennium, The Major, states: "Finally, the sea lion has left the ocean and is heading up the hill!"
Invasion: Alternative History of the German Invasion of England, July 1940 by Kenneth Macksey.
The Man in the High Castle, a 1962 novel by Phillip K. Dick.
Peace In Our Time (1946 – first performance 1947) by Noël Coward.
Resistance by Owen Sheers, which sets the successful invasion in 1944 after a failed invasion of Normandy rather than in 1940.
SS-GB by Len Deighton.
The Thursday Next novels by Jasper Fforde are set in an alternate universe in which Operation Sea Lion was successful. The German occupying force is eventually driven out, and by the time of The Eyre Affair England is a republic.
Weaver, 2008 novel by Stephen Baxter

Bedknobs and Broomsticks (1971)
Dad's Army (1971)
It Happened Here (1966)
Jackboots on Whitehall (2010)
Resistance (2011), a film about a group of rural Welsh partisans opposing the occupation of Britain.
Went the Day Well? (1942) is centered on a German radar-jamming mission for Sea Lion being eventually repulsed by the efforts of the civilian population of a remote village.

An Englishman's Castle (1978) is a British series set in an alternate history 1970s, in which Nazi Germany won World War II and occupies England. The protagonist Peter Ingram is a writer for a soap opera (also called An Englishman's Castle), which is set in London during The Blitz and subsequent Nazi occupation.^[1]
In a 2011 episode of Misfits, one of the many bizarre and supernatural events which "the gang" (as protagonists call themselves) is spending a time in Britain under the rule of a Nazi occupation force in an alternate reality where Germany won World War II.

Blitzkrieg (2012): part of the TSWW game system includes Sea Lion scenarios.
Britain Stands Alone: Operation Sealion, 1940 (1994)
Seelöwe (1974): featuring July/September scenarios (army and navy plans).
Their Finest Hour: The Battle of Britain and Operation Sea Lion (1982): part of GDW's Europa system.
Codeword Cromwell: The German Invasion of England, 8th June 1940 (2014): 5th Column Games

Axis & Allies (2004): while playing as the Axis powers in campaign mode (which has the Axis powers winning the war), Operation Sea Lion is the mission following the failed invasion of Normandy.
Battle Academy (2012) has an optional set of Sea Lion scenarios.
Britain Invaded!, aka Operation Sealion (1985)^[2]
Empire Earth (2001): the last mission of the German campaign is to carry out Operation Sea Lion.
Panzer General (1994): Sea Lion '40 and Sea Lion Plus (the latter with prestige points used to take over Gibraltar allowing Italian naval assistance) scenarios are available given major victories in early operations, or the Sea Lion '43 after initial delays and later major victories in North Africa or Russia.
Turning Point: Fall of Liberty (2008), a first-person shooter.
War Front: Turning Point (2007), a real-time strategy game.
Panzer Campaigns Sealion '40 (2010), operational wargame.